Press-on tool and method for pressing on a film to adhere to a substrate

ABSTRACT

Press-on tool for pressing on a film to adhere to a substrate. The press-on tool comprises a relatively hard and rigid carrier part with a press-on surface with which, during use, the film can be pressed against the substrate. The intermediate layer comprises a relatively soft, resilient cushion layer. Preferably, the cushion layer is non-slidably connected with the press-on surface and/or the carrier part. The invention also relates to a method for pressing on a film to adhere to a substrate.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a 371 of International Application Serial No.PCT/NL00/00793, filed on Nov. 2, 2000, which claims priority fromNetherlands Application Serial No. 1013473, filed on Nov. 3, 1999,granted as NL 1013473C on May 5, 2001, both entitled, “Press-On Tool andMethod for Pressing on a Film to Adhere to a Substrate.”

The invention relates to a press-on tool for pressing on a film toadhere to a substrate, comprising a relatively hard and rigid carrierpart with a press-on surface with which, during use, film can be pressedagainst the substrate, which press-on surface is at least partlyprovided with an intermediate layer with low friction.

Such a press-on tool is called “squeegee” by the skilled person and isopen used for applying self-adhesive plastic film to a substrate, forinstance a vinyl film provided with advertising imprint to a body partof a vehicle. An example of such a press-on tool is the PA-1 “plasticapplicator”_of the “gold” type, marketed by the enterprise 3M at StPaul, United States. The carrier part is designed as a substantiallyflat, elongated plastic spatula, whose longitudinal sides are eachprovided, on opposite sides, with press-on surfaces adjacent theiredges. The intermediate layer is friction-reducing and is formed by asleeve, which is loosely fitted over the press-on tool, such that thefriction between the press-on surface and the film is reduced. Thesleeve is marketed by the abovementioned enterprise under the name SA-1“Low Friction Sleeve”.

During use of the press-on tool, the film, after a self-adhesive sidethereof has been stripped of a protective sheet and has been placed onthe substrate, is manually pressed, with the help of the press-onsurface, to adhere to the substrate. The press-on surface is brushedover a reverse side of the film, provided with a protective layer, topress on the film and to remove entrapped air and folds. After the filmhas been pressed on so as to adhere, the protective layer is removedfrom the film.

A drawback of the known press-on tool is that it wears out relativelyrapidly. In particular irregularities on the surface to which the filmis applied relatively easily cause damage to the intermediate layerand/or the press-on surface, thus impeding uniform pressing-on of thefilm. Additionally, the sleeve causes a substantial decrease of the easeof use of the press-on tool. More in particular, the sleeve canunintentionally slide during use. Furthermore, when the friction betweenthe press-on surface and the film is insufficient for smoothening out,through intensive working, a part of the film, such as, for instance, afold, a tool has to be taken which has a press-on surface with a highercoefficient of friction. Hence, in practice, the press-on tool is oftenused without a sleeve, i.e., without the press-on surface being providedwith a friction-reducing intermediate layer. This leads to a substantialincrease of the effort and the time necessary for applying the film tothe substrate.

A further drawback of the known press-on tool is the necessity toprovide the film with a protective layer during pressing-on to preventdamage to the film due to the press-on surface or the intermediatelayer. This is the case in particular when pressing on pre-printed filmor film provided with cuts or interruptions, such as letters orcontours. In practice, this leads to the necessity of providing film tobe applied with a protective layer (again) after printing or cutting.

The object of the invention is to provide a press-on tool of the typementioned in the preamble, with which, while maintaining the advantages,the drawbacks mentioned are avoided. To that end, the press-on toolaccording to the invention is characterized in that the intermediatelayer comprises a relatively soft, resilient cushion layer. What is thusachieved is that the pressure exerted on the film by the press-onsurface can be distributed better and that irregularities in thesubstrate can be accommodated to. On the one hand, this leads to areduced chance of damage to the intermediate layer and/or the press-onsurface, so that the tool life of the press-on tool can be substantiallyprolonged. On the other hand, this leads to a substantial decrease ofthe chance of damage to the film. What is achieved in this manner isthat preprinted film and films having cuts or interruptions can, withoutany protective layer on the film, be pressed upon, which leads to asubstantial saving of time and material.

In a further embodiment, the cushion layer is connected in anon-slidable manner with the press-on surface and/or carrier part. Thecushion layer can be directly connected with the press-on surface, butcan also be provided on the press-on surface through an intermediatesupport part, for instance a rigid support disc. Preferably, the cushionlayer is connected with the press-on surface by means of a layer ofadhesive. Thus, the handling ease of the press-on tool is greatlyenhanced.

In another embodiment, the press-on tool comprises a further press-onsurface on which no cushion or intermediate layer is provided. What isthus achieved is that the press-on tool can be provided in a simplemanner with a further press-on surface with a higher friction forintensively working the film surface. When the carrier material has ahigher coefficient of friction than the material of the cushion orintermediate layer, this can be realized in a simple manner by givingthe intermediate layer dimensions such that a part of the carrier isfree to serve as a further press-on surface.

In yet another embodiment, the cushion layer is designed as a detachableadhesive strip of soft, resilient material. Thus, it is achieved thatthe cushion layer can be replaced in a simple manner.

In a still further embodiment, the cushion layer is made of felt. Whatis thereby achieved is that the pressure exerted by the press-on surfaceon the film can be very well distributed.

In a next embodiment, the cushion layer is designed as a woven. What isthereby achieved is that the cushion layer has a high resistance towear.

In yet another embodiment, the cushion layer is made of wool. What isthereby achieved is that the cushion layer can not only be very soft,but also very wear-resistant.

In a very advantageous embodiment, the cushion layer is designed as astrip of woolen, felted fabric with a layer of adhesive with which thestrip can be detachably provided onto the press-on surface.

The invention also relates to a method for applying film to a substrate,wherein, with the aid of a press-on surface of a press-on tool, film ispressed to adhere to a substrate and wherein, between the press-onsurface of the press-on tool and the film, a cushion layer is provided.When applying the film, contact pressure can be exerted through acushion layer with low friction, provided between the press-on surfaceof the press-on tool and the film. Preferably, during pressing-on, thecushion layer is contacted directly and without a further protectivelayer with a side of the film which is preprinted or provided with cutsor interruptions.

The invention further relates to a low-friction cushion layer for apress-on tool designed as an adhesive strip.

Further advantageous embodiments of the press-on tool and the method arerepresented in the subclaims.

The invention will be further elucidated on the basis of an exemplaryembodiment, represented in a drawing. In the drawing:

FIG. 1 shows a schematic perspective view of the press-on tool;

FIG. 2 shows a schematic perspective view of the press-on tool whilepressing the film onto a substrate; and

FIG. 3 shows a schematic perspective view of a cushion layer designed asan adhesive strip

It is noted that the drawings are only schematic representations of anexemplary embodiment of the invention. In the Figures, identical orcorresponding parts are designated by the same reference numerals.

FIGS. 1 and 2 show a press-on tool 1 for pressing on a film 10 to adhereto a substrate 12. The substrate 12 is substantially smooth, such as avarnished steel plate or plastic body part of a vehicle. The press-ontool 1 comprises a substantially flat, elongated plastic spatula 2. Thelongitudinal sides of the spatula taper and are each, adjacent the edge3A, 3B provided on both sides with press-on surfaces 4A, 4B, 4C and 4D.The press-on surfaces have a length of, for instance, 80-120 mm and awidth of, for instance, 0.5-5 mm, depending on the angle of incidencebetween spatula 2 and the substrate 12 and the degree of deflection ofthe spatula 2.

The press-on tool 1 is provided, adjacent the middle, with ribs 5 foroffering support to the fingers of a user when, during use, the press-ontool is manually pressed on the film 10.

The press-on surfaces 4A and 4B of the press-on tool 1 are provided withan intermediate layer with low friction, which is designed, with respectto the hard, rigid carrier material, as a relatively soft, resilientcushion layer. The cushion layer is compressible and is designed as anadhesive strip 6, which is applied over the press-on surfaces 4A and 4B.The adhesive strip 6 is made of felted woolen fabric 6A, provided at itsunderside with a layer of adhesive (FIG. 3). The layer of adhesive canbe designed as a strip of double-sided adhesive tape 7, so that thecushion layer is not slideably but detachably connected to the spatula2. The thickness of the cushion layer is preferably greater than orequal to approximately 0.5 mm, in particular greater than or equal toapproximately 1.0 mm. Further, the thickness of the cushion layer ispreferably less than or equal to approximately 5 mm, in particular lessthan or equal to approximately 2 mm. A very good result is obtained witha cushion layer having a thickness of approximately 1 mm. The adhesivestrip 6 can be supplied in a form already having suitable dimensions,but can also be separated from a larger strip which, for instance, hasbeen rolled up into a roll provided with predefined perforations.Referring to FIG. 2, during use of the press-on tool 1, the film 10,after a self-adhesive side 11 thereof has been stripped of a protectivelayer (not shown), is placed on the substrate 12 and, with the aid ofthe press-on surface 4B, pressed manually to adhere to the substrate 12.The press-on surface 4B is then brought in direct contact with thedisplay side 13 of the film, provided with letter incisions 14, printing15 and for interruptions 16.

In such case, a protective layer can be left out. The cushion layerprovides that entrapped air bubbles 17 and creases 18 in the film 10 canthen be smoothed out without damaging the display side 13, so that agood adhesion is effected between the film 10 and the substrate 12.

If necessary, a part of the film 10 which is to be worked moreintensively, for instance a part where a persistent fold 18 is presentin the surface, can be brought into contact with one of the press-onsurfaces 4C or 4D. These press-on surfaces are not provided with anintermediate or cushion layer and have a higher coefficient of friction.Then, only the position of the press-on tool 1 needs to be changed andno further press-on tool needs to be taken.

It is noted that, in this context, an intermediate layer having lowfriction must at least be understood to mean a layer with a coefficientof friction lower than the coefficient of friction of the spatulamaterial of a common plastic spatula, such as, for instance, the PA-1plastic applicator mentioned, which layer, during use, is positionedbetween the press-on surface and the surface of the film to be pressedon. In particular, an intermediate layer having low friction must beunderstood to mean a friction-reducing layer with a coefficient offriction which is in the order of, or which is lower than, thecoefficient of friction of the material of the SA-1 sleeve referred to.

It is also noted that the low-friction intermediate layer can beintegrated into the carrier part, for instance by providing therelatively soft, resilient intermediate layer on the press-on surface ofthe relatively hard, rigid carrier part by means of two-componentinjection molding. Further, the cushion layer can be provided on asupport disc which can be fitted on the carrier, for instance by meansof a snap or clamped connection. In addition, the cushion layer can beclamped directly onto the carrier or be stretched onto it. To supportthe clamping action, the cushion layer can be provided with stiffeningmeans, integrated into the cushion layer, such as an impregnated,resilient plastic or stiffening wires.

It is also noted that in FIGS. 2 and 3, the thickness of the film 10 andthe adhesive strip 6 are represented in an enlarged manner. Inparticular, this holds true for the thickness of the layer of glue onthe self-adhesive side 11 of the film and the strip of double-sidedadhesive tape 7.

It is further noted that the invention is not limited to the exemplaryembodiment discussed here and that many variant embodiments arepossible.

For instance, the carrier part of the press-on tool can be manufacturedfrom a different material than plastic, for instance wood, metal orcombinations of materials, and the press-on tool can be used forapplying film to windows, walls and boards. Further, the dimensions ofthe press-on tool can be chosen differently and the press-on tool can bepart of a machine with which film is mechanically pressed on asubstrate. This can be advantageous in particular when applying film toa door frame or window frame in substitution of a coat of paint. Thecushion layer can also be made of a non-woven material and theintermediate layer can be clamped onto the carrier. The carrier can alsobe entirely enveloped with a cushion layer. It is furthermore possiblethat the film is not self-adhesive, for instance when the substrate isprovided with a layer of adhesive or when the film can be adhered to thesubstrate by means of static electricity.

Such variants will be clear to the skilled person and are understood tofall within the scope of the invention as set forth in the followingclaims.

1. A press-on tool for pressing on a film to adhere to a substrate,comprising: a relatively hard and rigid carrier comprising opposite topand bottom sides with each of the top and bottom sides comprising twoplanar press-on surfaces located adjacent distinct edges, the planarpress-on surfaces of each of the top and bottom sides being spaced apartfrom each other; an intermediate layer comprising a relatively soft,resilient cushion layer having a coefficient of friction less than thepress-on surfaces; at least one of said planar press-on surfaces havingthe intermediate layer non-slidably connected thereto for contacting thefilm; and at least one other of said planar press-on surfaces being freefrom the intermediate layer.
 2. The press-on tool according to claim 1where said relatively hard and rigid carrier has at least two pairs ofpress-on surfaces on the opposite top and bottom sides of the relativelyhard and rigid carrier, the press-on surfaces of each pair beingseparated by an adjacent edge, the intermediate layer covering a portionof each press-on surface and the adjacent edge of at least one pair ofpress-on surfaces and the at least one other pair of press-on surfacesbeing free from the intermediate layer.